Sealed housing for a remote switching device

Abstract

A housing assembly (14) for protection of an enclosed printed circuit board (12) with a surface mounted dome switch (18) is disclosed. Various construction details are developed which provide sealing under a variety of atmospheric conditions. In one embodiment, the housing assembly is comprised of an upper portion (22), a lower portion (26), and a one piece, continuous diaphragm (30). The upper portion has an aperture (24) for engagement of a button actuator (20) by an external force. The diaphragm, composed of an elastic material, provides a sealed cavity (32) for the housing and permits substantial equalization between the internal and external pressure of the sealed cavity.

We claim: 
     
       1. An improved portable, remote switching device of the type having a switch and a housing assembly adapted to permit actuation of the switch by engagement between the housing and a force applying member, wherein the housing assembly comprises: a continuous first portion having a sealing groove extending peripherally about said first portion, said first portion being relatively rigid;   a second portion having an aperture which permits application of the force applying member to the switch, said second portion being relatively rigid and engaged with said first portion to form a junction therebetween and to provide a rigid outer shell adapted to protect the switch; and   a one piece, continuous diaphragm which extends from the junction between said first and second portions, said diaphragm being spaced from said first portion leaving a sealed cavity therebetween for the switch, the sealed cavity having no communication with the external environment of the sealed cavity, and said diaphragm having a flexibility characteristic which adapts said diaphragm to be readily moveable in response to a pressure difference between a pressure internal and a pressure external to the sealed cavity, wherein such movement includes said diaphragm pulling away from said second portion,   said diaphragm having a sealing bead which extends peripherally about said diaphragm, said sealing bead being disposed in the sealing groove in abutting contact with said first portion to provide a sealing force for said housing assembly and having a resilient spur which in an uninstalled condition has a lateral width wider than the sealing groove and in an installed condition has said spur compressed and deformed by bending in towards said diaphragm to increase the sealing force and to discourage said sealing bead from sliding out of said sealing groove.   
     
     
       2. The switching device according to claim 1, wherein said flexibility characteristic adapts said diaphragm to substantially equalize the difference in pressure across said diaphragm. 
     
     
       3. The switching device according to claim 2, wherein said flexibility characteristic adapts said diaphragm to eliminate the difference in pressure across said diaphragm. 
     
     
       4. The switching device according to claim 1, wherein said diaphragm is adapted to provide a soft, non-slip contact surface for the force applying member. 
     
     
       5. The switching device according to claim 1, wherein said diaphragm is adapted to provide a soft, non-slip contact surface for the force applying member. 
     
     
       6. An automobile switching assembly adapted to permit remote actuation of automotive devices by engagement with a force applying member, comprised of: an electrical assembly having a printed circuit board, a switch and a switch actuator;   a continuous lower portion having a sealing groove extending peripherally about said lower portion, said lower portion being relatively rigid;   an upper portion having an aperture which permits communication between the force applying member and said switch actuator, said upper portion being relatively rigid and joining said lower portion to form a junction therebetween and to provide an outer shell adapted to protect said electrical assembly against damage from impact;   a one piece, continuous, elastic diaphragm which extends from the junction between said upper portion and said lower portion to cover said electrical assembly, said diaphragm providing a sift, non-slip contact surface for the force applying member, said diaphragm having a flexibility characteristic which adapts said diaphragm to be movable in response to a pressure difference between the pressure internal and the pressure external to the sealed cavity, wherein such movement includes the diaphragm pulling away from said upper portion, said diaphragm in conjunction with said lower portion providing a sealed cavity for said electrical assembly, the sealed cavity having no communication with the external environment of the sealed cavity, said diaphragm having a sealing bead which extends peripherally about said diaphragm and which is disposed in said sealing groove in abutting contact with said first portion to provide a sealing force, said sealing bead having a resilient spur which in an uninstalled condition has a lateral width wiser than the sealing groove and in an installed condition has said spur compressed and deformed by bending in towards said diaphragm to increase the sealing force and to discourage said sealing bead from sliding out of said sealing groove.   
     
     
       7. The switching assembly according to claim 6, wherein said flexibility characteristic adapts said diaphragm to substantially equalize the pressure difference across said diaphragm. 
     
     
       8. The switching assembly according to claim 7, wherein the switch is a mechanically actuated switch. 
     
     
       9. The switching assembly according to claim 7, wherein said diaphragm includes a non-seal portion disposed radially inward of the sealing head, and wherein said flexibility characteristic adapts the entire non-seal portion of the diaphragm to move in response to a difference in pressure across the diaphragm to eliminate the difference between the pressure internal and the pressure external to the sealed cavity. 
     
     
       10. The switching assembly according to claim 6, wherein said upper portion and an adjacent, peripheral edge of said printed circuit board are adapted to provide lateral support to said diaphragm. 
     
     
       11. The switching assembly according to claim 6, wherein said upper portion and an adjacent, peripheral edge of said printed circuit board are adapted to provide lateral support to said diaphragm. 
     
     
       12. A method for providing a sealed cavity for a portable switching assembly, the switching assembly including a continuous lower portion having a sealing groove extending peripherally about the lower portion and a first mating edge, an upper portion having an aperture and a second mating edge adapted to engage the first mating edge in the assembled condition to form a junction therebetween, a one piece, continuous diaphragm which extends from the junction between the lower and upper portion and having a sealing bead extending peripherally about the diaphragm, the sealing bead having a resilient spur adapted to deform longitudinally by bending towards the diaphragm in the assembled condition, and an electrical assembly, comprising the steps of: (a) positioning the electrical assembly between the lower portion and the diaphragm with the sealing groove and the sealing bead aligned;   (b) positioning the upper portion over the lower portion with the diaphragm therebetween, with the first mating edge and second mating edge aligned;   (c) applying a force to the upper portion and lower portion such that the upper portion drives the sealing bead vertically down into the sealing groove and the sealing groove exerts a longitudinal force longitudinally compressing and deforming the resilient spur; and   (d) securing the upper portion to the lower portion.   
     
     
       13. An improved portable, remote switching device of the type having a switch and a housing assembly adapted to permit actuation of the switch by engagement with a force applying member, wherein the improvement comprises: a continuous first portion having a sealing groove extending peripherally about said first portion;   a one piece, continuous diaphragm having a sealing bead which extends peripherally about said diaphragm, said sealing bead being disposed in the sealing groove in abutting contact with said first portion to provide a sealing force for said housing assembly, wherein said sealing bead has a resilient spur which in an uninstalled condition has a lateral width wider than the sealing groove and in an installed condition said spur compressed and deformed by bending in towards said diaphragm to increase the sealing force and to discourage said sealing bead from sliding out of said sealing groove, wherein said diaphragm is spaced from said first portion leaving a sealed cavity therebetween for the switch, the sealing cavity having no communication with the external environment of the sealed cavity, and said diaphragm having a flexibility characteristic which adapts said diaphragm to be readily moveable in response to a pressure differential between a pressure internal and a pressure external to the sealed cavity.